Compound bearing



Dec. 26, 1961 J. P. wATsoN 3,014,382

COMPOUND BEARING originai Filed sept. so, 195s 2 sheds-sheet 1///L////Z///////// jid IN V EN TOR.

v SAM PUJA@ Dec. 26, 1961 1. P. wATsoN 3,014,382

COMPOUND BEARING Original Filed Sept. 30, 1955 2 Sheets-Sheet 2 I N VENTOR.

United States Patent O 3,014,382 CGMPOUND BEARING James P. Watson,Ingiewood, Calizi., assigner of one-half to .loe Davidson, South Gate,Caiit.

Original appiieation Sept. 30, 1955, Ser. No. 537,711, now Patent No.2,884,573, dated Apr. 28, 1959. Divided and this application Feb. 2,1959, Ser. No. '790,649

6 Claims. (Cl. 74-590) This invention relates to acceleration proofactuating members, and more particularly to improved counterbalance orcounterweight means for the armature of an electromagnet, such as theplunger of a solenoid.

It is an object of this invention to provide a counterbalance orcounterweight means for a reciprocably mounted member which does notappreciably increase the overall volume or bulk of the completedapparatus.

It is another object of this invention to provide counterweight meansfor a reciprocably mounted member having such conguration that stressesand strains in the linkage between the member and its counterweight arereadily absorbed in the counterweight itself, which by its very naturemay be made heavy and strong, thus allowing the associated parts of theapparatus to be only slightly larger than would otherwise be required.

it is another object of this invention to provide counterweight meansfor a reciprocable member in which the linkage mechanism between themember and its counter- Weight is small in both bulk and weight, wherebythe principal weight increase of the apparatus is in the counterweightitself, where it can be employed to full advantage.

It is a further object of this invention to provide such a counterweightmeans as above, which is simple, rugged, and economical to manufacture,assemble, and maintain.

It is a further object of this invention to provide counterweight meansfor a solenoid plunger which may be readily adapted and applied toexisting solenoids and plungers.

It is a further object of this invention to provide counterweight meansfor a solenoid-operated plunger which can be applied with only a veryslight increase in the overall length of the apparatus, and with noincrease in diameter; or alternatively with slight increase in diameterand no increase in length.

It is another object of this invention to provide counterweight meansfor a solenoid-operated plunger which can be applied to a singlesolenoid and plunger.

lt is a further object to provide an improved bearing arrangementbetween plunger, standard, and counterweight of the type mentionedabove.

it is a still further object to provide, in an arrangement of the abovetype, means for producing rotation of the plunger with each strokethereof.

It is another object to provide either linear counterbalancing along thelongitudinal axis of a plunger, or rotational counterbalancing aboutsuch an axis.

in accordance with these and other objects which will become apparenthereinafter, preferred forms of the present invention will now bedescribed with reference to 'the accompanying drawings, wherein:

FIG. l is a longitudinal section illustrating an embodiment of thepresent invention;

FIG. 2 is a cross-section taken on line 2-2 in FIG. l;

FIG. 3 is a cross-section taken on line 3 3 in FIG. l;

FIG. 4 is a longitudinal section taken on line 4-4 in FIGS. l and 3;

FiG. 5 is a cross-section taken on line 5-5 in FIG. l;

FIG. 6 is a perspective View illustrating another form of the presentinvention, being in particular an alternative way of constructing acertain portion of the embodiment shown in FIG. 1 and fice FIG. 7 is across-section taken on line 7-7 in FIG. 6.

Referring to the drawings, the counterweight means of the presentinvention is shown as applied to a reciprocably mounted member in theform of a plunger 11d actuated by an electromagnet solenoid (not shown)disposed coaxially circumjacent the plunger 11d and contained within acase or housing 13d. At least one end of the plunger 11d projectsupwardly through a central opening in the top wall of the housing 13d,and the upper end of the plunger has a rod 64 for receiving any suitabiemember to be actuated by movement of the plunger 11d. The plunger 11d ismounted for reciprocation in conventional fashion within the solenoidcoil. In the typical case, suitable means such` as spring 61 areprovided or biasing the plunger 11d upward, and the plunger is drawndownward against the bias by electromagnetism whenever the coil isenergized.

Proper operation of the solenoid requires that the plunger 11d be movedonly when the coil is energized. Under conditions of severe accelerationoccurring longitudinally of the plunger, as, for example, under shock orother high acceleration forces, suicient force on the plunger 11d mightbe imparted to cause undesired actuation of the part connected to theplunger 11d in either direction, or to block normal operation in eitherdirection.

In order to overcome and guard against such undesired actuation of theplunger 11d, counterweight means are provided in the form of acounterweight disposed substantially symmetrically coaxially of thereciprocation path of the plunger 11d. The counterweight is also mountedfor reciprocation along said path. In the form of the inventionillustrated in FIGURES 1 5, the counterweight is shown as being oftubular coniguration in the form of a tube or cylinder 17d.

The counterweight 17d is linked to the plunger 11d through theintermediacy of a standard formed by a sleeve Idd projecting upwardlyfrom the top of the housing i3d coaxially of the plunger 11d anddisposed intermediate the plunger 11d and the counterweight 17d.Journaled in the sleeve 18d on a substantially tangential shaft is asmall gear or pinion 21d, which meshes with rack teeth formed on theadjacent interior surface of the counterweight 17d and with rack teethformed on the adjacent surface of the plunger 11d. Such engagementbetween pinion Zid, and plunger 11d and counterweight 17d, respectively,serves to transmit motion of the plunger 11d to the counterweight 17d inopposite directions. rihus, when the plunger 11d is drawn downward, lthecounterweight 17d is caused to move upward, and vice versa. By makingthe weight of plunger 11d equal to that of counterweight 17d, a balancedassembly is effected, which is unaffected by acceleration forces thatmight otherwise cause undesired, or block normal, reciprocation of theplunger 11d.

When used in connection with a solenoid, the plunger 11d must, ofcourse, be made of magnetic material. It is preferred to make thecounterweight 17d of non-magnetic material in order to avoid deleteriousmagnetic action between the coil and counterweight 17d.

In order to keep the rack teeth in firm engagement with the teeth of thepinion 21d, and to form a bearing surface between the standard andplunger and standard and counterweight, respectively, elongate ballraces 54 are provided. As shown in FIG. l, the cylindrical standard 18dis disposed circumjacent the plunger 11d and within the counterweight17d. The standard 18d is made in three parts, as shown in FIG. 2, whichhave adjacent surfaces S6 disposed obliquely with respect to radiiemanating from the center line, or axis 55, of the device. The adjacentsurfaces 56 are suitably recessed or grooved, to form therebetweenelongate, endless ball-races 54 G filled with suitable roller members inthis present instance balls 57.

Each race 54 is comprised of an inside track 28d located between theplunger 11a.' and the standard 18 an outside track 27d located betweenthe counterweight 17d and the standard 18d; an upper crossover track 58joining the tracks 27d and 28d at their upper reaches; and a bottomcrossover track 59 joining the tracks 27d and 28d at their bottomreaches.

The oblique disposition of the parting lines or surfaces 56 has thedouble advantage of giving a greater length for the balls 57 to make the180 turn at 58 and S9, and of displacing the parting line from theradial pressure line which runs through the tracks 27d and 28d. Locatingthe ball races 54 at the parting lines or surfaces 56 permits readymachining or" the races into the two adjacent surfaces, as shown in FIG.3, and also simplifies loading of the balls into the races prior toassembly of the three parts forming the standard 18d. The necessity fora loading portion with consequent plugging up of the port is thusobviated.

As will be readily appreciated in FIG. l, as the plunger 11d moves downwithin the standard 18a', the balls 57 in the inside track 28d will berolled downward into the lower crossover 59 and thence upward into theouter track 27d. At the same time, the pressure of the counterweight 17don the balls 57 in the outer track 27d, causes the outer balls to berolled upward, Thus the flow of balls in the two tracks agrees with therespective movements of the plunger and counterweight, and except forthe balls in the crossover tracks 58 and 59, all balls are constantly inuse. Thus, there is no idle return race in which the balls must bereturned unused, or dead-heading, as it were.

The tracks 27d and 23d of the race 54 are partially formed by providinga shallow, but well defined longitudinal groove in plunger lid andcounterweight 17d, respectively. This furnishes a rolling keying actionpreventing rotational displacement of both the plunger and counterweightwith respect to the standard 18d.

A further feature of the embodiment shown in FIG. 1-5 is the positioningof the return spring for the plunger 11d, outside of the useful coilfield.

As a rule, solenoid return springs are placed in complementary facingrecesses, one recess being formed in the complementary face of a stop oranvil, which is stationarily mounted within the solenoid coil and fixedwith respect to the housing. Such recessing of the complementary facesbetween the plunger and anvil, in order to accommodate the returnspring, of necessity decreases the magnetic seal-in surface between thetwo when the plunger is fully pulled in by the solenoid. Thus themagnetic pull tending to hold the solenoid in closed position isconsiderably decreased. Furthermore, the formation of the recesseswithin the active part of the magnetic field of the coil decreases theamount of iron in the plunger 11d, with consequent decrease in thepull-in force.

In the embodiment shown in FIG. 1, the return spring 61 is placed in anelongate slot 62 formed in the side of the plunger 11d. The bottom ofthe spring 61 rests on a shelf 63 projecting into the slot 6-2 andformed integral with the standard 18d. The slot 62 is also ernployed asa convenient means for retaining an operating rod 64 secured to theouter end of the plunger 11d. To this and the upper end of the slot 62is enlarged, as shown at 66 (FIG. 5), to slidably receive a head 67formed on the bottom end of the operating rod 64 and staked to theplunger 11d at the two corners 70. The undersurface of the head 67 isrecessed at 68 to receive the upper end of the spring 61, as shown inFIG. 1. The slot 62 is continued through to the upper end of the plunger11d, being at this point ensmalled properly to receive the rod 64.

The assembly thus described and illustrated in FIGS. 1 5 is assembledand held together by means of a bottom retaining ring 71, into which thethree sections of the standard 18d are press-htted from below, and anupper retaining ring 72 press-tted around the upper' edge of thestandard 18d, into a groove formed therearound, as shown in FG. l.

The assembly is secured as a unit to the solenoid housing 13d by meansof four bolts residing in bolt holes 73, and screwed into the top of thehousing 13d. A shoulder 74 serves to longitudinally position thestandard 18d within the bottom ring 71.

A loose fitting, pliant dust cover 76 is secured in place over theentire assembly, so as to keep dust and other contaminants out of theworking parts; it preferably also covers the bolt holes 73 to completelyseal the unit. The actuating rod 64 projects through the cover 76 so asto be connected to any suitable part to be actuated. The cover 7 6 is ofsuicient size and pliancy so that when the plunger 11a retracts, pullingthe cover downward, the sides of the cover may bulge outward toaccommodate the air inside the cover, which would otherwise build up anobstructing pressure.

The embodiment shown in FIGS. l-S may be completely assembled apart fromthe solenoid proper and may, as a unit, replace a standard plunger- Thisis accomplished merely by removing the standard plunger from thesolenoid and bolting the assembly shown in FIG. 1 to the top of thehousing 13d, the plunger 11d of the assembly serving to replace thestandard plunger.

In view of the fact that the standard 18d is made in three parts, theapparatus shown in FIG. 1 may be readily assembled without requiring anextension of the rack groove. As will be readily seen in FIG. 3, theball races 54 are so positioned that one is diametrically opposite thepinion 21d, thereby serving to absorb the force exerted diametrically bythe pinion 21d.

When the assembly shown in FIG. l is separated from the solenoid proper,the presence of the spring 61 serves as a stop, limiting downwardmovement or" the plunger 11a', so that the pinion 21d is at all timeskept in engagement with the rack-teeth on the plunger and counterweight.

In FIGS. 6 and 7, there is illustrated another form of the presentinvention which is essentially a modification of the form shown in FIGS.1-5.

In this embodiment the standard 18d of FIG. l has been replaced by astandard 18e in which the ball-races 54e, instead of being essentiallystraight and parallel to the aXis of the standard 18e, are skewed inhelical fashion in the manner of a thread. Since the balls partiallymate in corresponding helical grooves in the plunger and counterweight,respectively, it follows that each stroke of the plunger causes it torotate as well as to move longitudinally. In similar fashion, thecounter-weight is also caused to rotate, and since the counterweight ismoving longitudinally in a direction opposite to that of the plunger,its rotation is likewise opposite and equal to that of the plunger.

Thus, the counterweight tends to counterbalance or offset the rotationalinertia of the plunger as well as the linear inertia. Suchcounterbalancing is not complete, since the counterweight has a greatermoment of inertia and therefore its rotational inertia is greater thanthat of the plunger. Thus, while the magnitudes of the rotationalcounterbalancing are different, they are in opposite directions, andthere is some tendency for counterbalancing rotationally. Completerotational counterbalancing may be achieved by making the rotationalinertia of plunger and counterweight equal, in which case linearcounterbalancing would be incomplete.

The structure shown in FIG. 6 has particular applicability in thoseinstances where it is desired to cause the operated part to rotate aswell as to reciprocate longitudinally. Such might be the case, forexample, with a piston which reciprocates in a cylinder. By inserting anoverrunning or one-way clutch between the plunger and the piston rod,the rod can be caused to rotate in one direction with each stroke, andthus eliminate a tendency for grooves to be worn into the piston andcylinder.

In the embodiment shown in FIGS. 6-7, the pinion 21e linking the plungerand `counterweight is canted at an angle corresponding to the pitchangle of the rack teeth in plunger and counterweight, which teeth areset at an angle corresponding to the helix angle of the races 54e.

It Will be understood that in the embodiment of FIGS. 6-7, the biasspring cannot be conveniently arranged inthe manner shown at 61 in FIG.1, because the helical shape of the races 54e prevents employment of theshelf 63. Hence in this embodiment the return spring would be of themore conventional type described hereinbefore.

This is a division of application Serial No. 537,711 filed September 30,1955, now Patent No. 2,884,573, issued April 28, 1959, applicant JamesP. Watson, for Acceleration Proof Acting Member.

While the instant invention has been shown and described herein in whatis conceived to be the most practical and preferred embodiments, it isrecognized that departures may be made therefrom within the scope of theinvention, which is therefore not to be limited to the details disclosedherein, but is to be accorded the full scope of the claims.

What is claimed is:

l. Bearing means comprising a first member, a second member movablerelative to said first member, a third member movable relative to saidfirst and second members, an endless bearing race disposed between saidfirst and second members and between said first and third members andpresenting spaced surfaces between said first and second members andbetween said first and third members; and roller members in said race infree-rolling relationship with said surfaces and forming bearing meansbetween said first and second members and between said first and thirdmembers.

2. Bearing means comprising a first member, a second member movablerelative to said first member, a third member movable relative-to saidfirst and second members, an endless bearing race disposed between saidfirst and second members and between said first and third members andpresenting spaced surfaces between said first amd second members andbetween said first and third members, roller members in said race in`free-rolling relatonship with said surfaces and forming bearing meansbetween said first and second members and between said first and thirdmembers; and means for coupling together said second and third members.

3. Bearing means comprising a first member, a second member movablerelative to said first member, a third member movable relative to saidfirst and second members, an endless bearing race disposed between saidfirst and second members and between said first and third members andpresenting spaced surfaces between said first and second members andbetween said first and third members, roller members in said race infree-rolling relations'nip with said surfaces and forming bearing meansbetween said first and second members and between said first and thirdmembers, said second and third members being disposed to move parallelto said bearing race.

4. Bearing means comprising a first member, a second member movablerelative to said first member, a third member movable relative to saidfirst and second members, an endless bearing race disposed between saidfirst and second members and between said first and third members andpresenting spaced surfaces between said first and second members andbetween said first and third members, roller members in said race infree-rolling relationship with said surfaces and forming bearing meansbetween said first and second members and between said first and thirdmembers, said first member being interposed between said second andthird members.

5. Bearing means comprising a tubular standard, a plunger reciprocablewithin said standard, a counterweight cireumjacent said standard andreciprocable with respect thereto, an endless bearing race disposedbetween said standard and plunger, and between said standard andcounter-weight, and roller members in said race forming bearing meansbetween said standard and plunger and between said standard andcounter-weight.

6. Bearing means comprising a tubular standard, a plunger reciprocablewithin said standard, a counter-Weight circumjacent said standard andreciprocable with respect thereto, an endless bearing race disposedbetween said standard and plunger and between said standard andcounter-weight, roller members in said race forming bearing meansbetween said standard and plunger and between said standard andcounter-weight, and said bearing race being disposed on a generallyhelical path both internally and externally of said standard.

References Cited in the file of this patent UNITED STATES PATENTS1,737,390 Roe Nov. 26, 1929 2,513,934 Hall July 4, 1950 2,520,785Schlicksupp Aug. 29, 1950l 2,628,135 Magee Feb. 10, 1953 2,708,285Greenspon et al. May 17, 1955 2,832,921 Harman Apr. 29, 1958 2,883,244Berger Apr. 2l, 1959 2,884,573 Watson Apr. 28, 1959 FOREIGN PATENTS488,549 Italy Dec. 28, 1953 1,012,793 Germany July 25, 1957

